Funding support is requested for a MALDI-TOF-TOF mass spectrometer with associated liquid chromatography and spotting robot that are essential to many NIH-funded research programs. To ensure maximum availability, proper maintenance and best use of NIH funds, the instrument will be placed in the UCI Mass Spectrometry Facility, the Director of which has over 30 years experience. The facility does not have a MALDI-TOF-TOF. UCI has long supported the Facility and this has been dramatically increased this year with the addition of funding for a protein mass spectrometrist and a $150,000 renovation of 3,500 square feet of space to re-house the facility that includes dedicated rooms for protein sample preparation and protein MS. Also $90,000 is committed to the instrument budget. Normal operational funds are obtained though recharge. The Facility is well equipped and heavily used, particularly for small molecule analysis using Open Access technology, analyzing 20,000 samples a year by flow injection ESI, C18-LC-ESI-MS and GC-MS. However, the research below shows that there is an urgent need to expand the protein analysis capability beyond the old and no longer manufactured MALDI-TOF (single analyzer) instrument and a QTOF that is not appropriate or sufficiently sensitivity. The research projects to be supported are spread across the Schools of Physical Sciences, Biological Sciences and Medicine and the instrument will, therefore, be truly a shared inter-disciplinary resource. Research projects of the major users include: a) Professor Weiss (PI): Sequencing of mutants of the membrane protein caveolin selected after engineering of phage solubilized protein;analysis of peptide epitopes modified with potentially therapeutic agents for HIV inhibition and designed to counteract the issue of HIV mutability. b) Professor Aswad: Activity of L-isoaspartyl methyltransferase in the methylation of damaged proteins and repair of atypical isoaspartyl residues by conversion of the isopeptide bond to a normal peptide bond;investigating the role of protein-arginine methylation in the regulation of gene expression, particularly concerning arginine methyltransferase 4 activity. c) Professor James: Mosquito egg shell proteins sequencing to study evolutionary divergence of Aedes and Anopheles mosquitoes and potentially a new pathway for vector control. d) Professor Sandri-Goldin: Understanding arginine methylation as a molecular switching mechanism in the herpes simplex virus regulatory protein, ICP27, a multifunctional protein whose activities are modified during the time course of infection. e) Professor Shea: Development of epitope recognition polymers that can act like synthetic antibodies. f) Professor Walsh: The role that apoptotic signal transduction plays in the development, activation and homeostasis of the immune system. Other NIH-funded research groups will be provided access to the instrument when possible. PUBLIC HEALTH RELEVANCE: Funds are requested for a MALDI-TOF-TOF mass spectrometer and associated equipment that is essential for undertaking analytical chemistry in support of fundamental research into organism metabolism in various disease states. These include: i) Virus research, mechanisms of virus metabolism and control including HIV and Herpes simplex;ii) Cell regulation, control of cell activation, cell death and restoration of aging proteins;iii) Insect metabolism, mosquito evolution and alternative methods of malarial mosquito control and iv) Development of synthetic antibodies.